code: def test_toy_meta_dataset(dataset_class):
      dataset = dataset_class(10, num_tasks=1000, noise_std=None)
  
      assert isinstance(dataset, MetaDataset)
      assert len(dataset) == 1000
  
file_path: pytorch-meta/torchmeta/tests/toy/test_toy.py
imports: import pytest
  import numpy
  from collections import OrderedDict
  from torchmeta.utils.data import Task, MetaDataset
  from torchmeta.toy import Sinusoid, Harmonic, SinusoidAndLine
  from torchmeta.toy import helpers
label_desc: Use image node_id 1 for calling a global function with example usage: test_toy_meta_dataset(dataset_class) without return types